The study on inclination feature model of tower crane under the condition of severe overload

In common condition we can say that the tower crane is overloaded when the value of lifting load is far more than that of design. As a matter of fact, because of the influences of wind load and loose bolts some collapsed accidents of tower crane took place while lifting load was less than design value. So in this paper a model named TLIM (tower crane loading inclination feature model) is established based on TCBIM (tower crane body inclination model). There are three differences between TLIM and normal healthy model: first, the coordinate of tower body top inclination is in the front of TCBIM when it is under the condition of severe overload; second, it is can be defined that the critical collapsed state is the suitable external envelope of tower body top inclination; at last, the angle difference δ_θ between tower body top inclination and TCBIM is measurable. It is proved in this paper that the model TLIM is correct through analyzing experimental data, and not only is it significant to the auto-detect of tower collapsed accidents caused by overload, but also a feasible method for people to monitor and prevent tower from collapsing.